I forgot the name of this manga.
I story: Its a student (seme) and teacher (uke) relationship. The student has personal problems. Something wrong with his mother, they live apart. II story: Its about high school(?) boy who falls in love with his sisters husband. Sis and his hsband have a child, but that girl never at home. First and second story are connected -> student from chapter I is that husbands nephew. And high school boy is jeallous of that nephew. Hope someone knows that manga 😀

Sekai wa minikuidesu..shika shi! Yūjō, yūki, tsuyo-sa wa ikinokoranakereba narimasen..Tiruendo!